Abstract：According to the optimization design of graphene oxide (GO) layered composites and their high sensitivity to environmental humidity, the interlayer shear behaviors of GO in humid environment have been studied. Firstly, expressions of interlayer cohesive energy, interlayer hydrogen bond (HBond) interaction and shear stress have been obtained by employing theoretical models. Good agreements can be achieved for the results obtained by theoretical models and molecular dynamics simulations. Different numbers of water molecules have been further introduced into the interlayer of GO structures. Then, interfacial properties of GO composites can be improved by adjusting oxidation concentrations and contents of interlayer water molecules, which determine the interlayer HBonds networks. The results show that increasing the oxidation concentration can effectively increase the density of the interlayer HBonds networks, thus improving the interlayer shear strength of GO structures. However, an optimal oxidation concentration can be obtained for GO structures with limited sizes, where enhancement of shear stress of GO will reach saturation. In this situation, introducing water molecules into interlayers of GO structures can further enhance their shear strength, and an optimal content of water molecules has also been observed. The research put forward a simple numerical method to evaluate HBond energy and propose two ways to improve the mechanical properties of GO layered composites. During these processes, the effect of HBonds networks on interlayer shear properties of GO composites has been highlighted. This study should be of great importance to providing a significant theoretical support for designing GO-based composites.
2021, Vol. 42 
